Anthropic is introducing machine-readable marking technology for its Claude series of AI models. All text generated by Claude will be embedded with invisible watermarks, while images and other files will have digitally signed provenance metadata attached. This move aims to enhance AI content transparency and responds to Article 50, Paragraph 2 of the EU AI Act, the "Code of Conduct on Transparency for AI-generated Content," which requires new Claude models launched in the EU from August 2, 2026, to support content marking. Anthropic stated that the marking mechanism will apply globally, covering all Claude product lines and partner cloud platforms.